Traditionally, cryptographic implementations were designed to resist only black-box attacks. These are attacks where an adversary attempts to deduce the cryptographic key inside the implementation by analyzing only inputs and outputs. In a black-box attack, it is assumed that the adversary knows what family of cryptographic algorithm they are targeting (e.g., AES, DES, RSA, etc.), but all other details (e.g. execution time, power consumption, memory accesses) are unavailable to them. In essence, a black-box attacker treats the implementation as a mathematical function. However, a white-box attacker is a much more powerful type of adversary and can analyze all parts of the implementation. Rather than just study inputs and outputs, a white-box attacker can see everything that goes on inside the implementation. For example, if the attacker is targeting cryptographic software running on, say, a PC or mobile phone, then they can execute that software inside a debugger and examine memory and register values during its execution. Conventional software implementations of cryptographic algorithms are completely insecure against white-box attackers since the cryptographic key can be observed in memory. New implementations of cryptographic algorithms that resist white-box attacks have recently been proposed (e.g., AES [1], DES [2], ECDSA [3], SHA [4]); however, there have not yet been any proposals for protecting key agreement algorithms, such as Diffie-Hellman [5].
The systems and methods disclosed herein provide techniques for implementing a key agreement scheme that resists white-box attacks.